AMBER is a suite of programs and a force field for molecular mechanics-based simulation. It is designed primarily for proteins and nucleic acids. It includes: energy minimization, dynamics, NMR restrained dynamics, and free energy and normal mode calculations. It is developed and maintained by the Kollman group, with collaborators at other sites, and distributed worldwide by the Kollman group. A new, X-windows graphical interface (Leap) has just been released with AMBER 4.1. Specifically, I use the resources at the Computer Graphics Laboratory to run verification suites on DEC and SGI computers to ensure correct compilation and add workarounds for SGI compiler bugs; also I develop the X11R4 version of Leap on SGI machines. I coordinate with collaborators and users using Internet access, and make workstation tapes on SGI machines.